Deoxyribozymes inhibit the expression of period1 gene in vitro

To investigate the effect of two deoxyribozymes targeting period1 (per1) mRNA in vitro for exploring a novel gene therapy approach about circadian rhythm diseases, the specific deoxyribozymes targeting per1 were designed and synthesized chemically following MFold analysis according to its mRNA secondary structure. per1 RNA fragments were prepared by in vitro transcription of pcDNA3.1(+)-per1(164:256). The cleavage reactions containing deoxyribozymes and per1 RNA fragments were performed under certain conditions. With the transfection technique mediated by LipofectAMINE, pcDNA3-per1 and DRz164 or DRz256 were introduced into NIH3T3 cells. The effects of deoxyribozymes on per1 were studied by reverse transcript-polymerase chain reaction (RT-PCR) and flow cytometry (FCM). When deoxyribozymes and RNA transcripts were incubated under the adopted conditions at 37 degrees C for 2 h, about 63% of per1(164:256) RNA transcripts were cleaved by DRz164 and about 50.5% by DRz256. After cotransfecting pcDNA3-per1 with DRz164 or DRz256, the expression of per1 mRNA was decreased, as indicated by RT-PCR semi-quantity analysis. FCM analysis showed that Per1 protein was inhibited. Both DRz164 and DRz256 targeting per1 have the specific cleavage activity toward per1 mRNA in vitro and can highly block the expression of per1 gene in cellular milieu.